Optical device and method for making the same

ABSTRACT

A method for making an optical device includes the steps of: rubbing an orienting film so as to stretch the molecular structure thereof and so as to permit the molecular units of the molecular structure to be aligned along a first axis and to permit the orienting space between each adjacent pair of the molecular units of the molecular structure to be oriented in a direction parallel to a second axis; and forming an optical anisotropical layer on the orienting film by applying a liquid crystal film of rod-like molecules on the orienting film which orients the rod-like molecules by virtue of spatial effect of the molecular units and the orienting spaces.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese Patent Application No.093129218, filed on September 27, and No. 093137027, filed on Dec. 1,2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an optical device and a method for making thesame, more particularly to a method using an orienting material havingmolecules with a molecular structure that is stretchable and that hasmolecular units and orienting spaces which are capable of orientingrod-like liquid crystal molecules of a liquid crystal material.

2. Description of the Related Art

Conventional compensators, which serve as phase retarders for correctingretardation or phase difference in a liquid crystal cell of a liquidcrystal display so as to improve the viewing angle, the contrast, andthe grey scale of the liquid crystal display, are commonly made by apolycarbonate film, which is required to be stretched along a machinedirection (MD) or film moving direction. As a consequence, theextraordinary axis of the thus formed compensators is parallel to themachine direction. As such, the compensators cannot be attached to apolarizer in a roll-to-roll manner when the extraordinary axis of thecompensator is to be formed an angle with an absorbing axis of thepolarizer.

Optical compensators made from anisotropical materials of liquid crystalmolecules are also known in the art.

The compensators are made by aligning the liquid crystal molecules on asubstrate using an orienting film which is rubbed along a directionparallel to the machine direction. As a consequence, the projection ofthe orientation of the liquid crystal molecules of the thus formedcompensator on a plane defined by the substrate is parallel to the filmmoving direction or the machine direction. Note that the compensatorsare normally produced in the form of rolls. Since the projection of theorientation of the liquid crystal molecules of a compensatory roll isparallel to the machine direction, the compensatory roll cannot bedirectly attached to a polarizer roll in a roll-to-roll manner forpreparing a polarization element having a function of a quarter waveplate, which can generate a phase difference of λ/4 at a wave length of550 nm, or a function of a half wave plate, which can generate a phasedifference of λ/2 at a wavelength of 550 nm.

FIG. 1 illustrates a polarization element that includes a polarizerpiece 1 and a compensator piece 21 cut from a compensator roll forattaching to the polarizer piece 1. In order to serve as a quarter waveplate, the compensator piece 21 is required to be cut from thecompensator roll in such a manner that the projection 211 of theorientation of the liquid crystal molecules of the compensator piece 21forms an angle of 45 degrees with the lengthwise direction (L) of thecompensator piece 21, which is parallel to the absorbing axis 11 of thepolarizer piece 1.

FIG. 2 illustrates a polarization element that includes a polarizerpiece 1 and first and second compensator pieces 21, 22 that are cut froma compensator roll for attaching to the polarizer piece 1. In order toserve as a quarter wave plate, the first compensator piece 21 isrequired to be cut from the compensator roll in such a manner that theprojection 211 of the orientation of the liquid crystal molecules of thefirst compensator piece 21 forms an angle of 75 degrees with thelengthwise direction (L1) of the first compensator piece 21, and inorder to serve as a half wave plate, the second compensator piece 22 isrequired to be cut from the compensator roll in such a manner that theprojection 221 of the orientation of the liquid crystal molecules of thesecond compensator piece 22 forms an angle of 15 degrees with the lengthwith direction (L2) of the second compensator piece 22. The lengthwisedirection (L1) of the first compensator piece 21 and the lengthwisedirection (L2) of the second compensator piece 22 are parallel to theabsorbing direction of the polarizer piece 1.

As such, mass production using the aforesaid compensators is difficultto achieve, and a large manpower for assembling the compensator piecesand the polarizer pieces is required.

U.S. Pat. No. 6,262,788 discloses a process for preparing an opticalretardation film. The process is capable of permitting mass productionof the retardation film in a roll-to-roll manner. The process uses aroller set for conveying a compensator substrate. The compensatorsubstrate is continuously rubbed upon moving in a moving direction foralignment of liquid crystal molecules of a liquid crystal film thereon.

Although, theoretically speaking, the aforesaid process is capable ofproducing the retardation film with the liquid crystal molecules alignedin a direction that forms an angle ranging from 0 degree to 90 degreeswith the machine direction or the lengthwise direction of the substrate,the process is relatively complicated due to the use of the roller setin the manufacturing process, and the quality of the product isdifficult to control. Moreover, when a rubbing angle is greater than 45degrees or smaller than −45 degrees, rubbing parameters during rubbingof the compensatory substrate and tension of the compensatory substrateduring conveying of the compensatory substrate are difficult to control.

U.S. Pat. No. 6,531,195 discloses an orienting layer of a copolymer fororienting liquid crystal molecules of an anisotropical layer thereon forpreparing an optical compensatory sheet. The aforesaid orienting layeris disadvantageous in that the orientation of the liquid crystalmolecules of the anisotropical layer can only be aligned by theorienting layer in a direction perpendicular to a rubbing direction orthe machine direction.

Hence, there is a need to develop an orienting layer that is capable oforienting the liquid crystal molecules of an anisotropical layer of acompensator, which is in the form of a roll, such that the projection ofthe orientation of the liquid crystal molecules of the anisotropicallayer forms an angle ranging from 0 degree to 90 degrees with themachine direction, thereby permitting assembly of the compensator andthe polarizer in a roll-to-roll manner.

SUMMARY OF THE INVENTION

Therefore, the object of this invention is to provide a method formaking an optical device that is capable of overcoming the aforesaiddrawbacks of the prior art.

Another object of this invention is to provide an optical device that iscapable of providing a wide-band compensating effect.

According to one aspect of the present invention, a method for making anoptical device comprises the steps of: (a) providing an orienting filmthat is made from an orienting material having molecules, each of whichhas a molecular structure that is stretchable and that has a series ofconnected molecular units, each adjacent pair of the molecular unitsdefining an orienting space therebetween; (b) rubbing the orienting filmso as to stretch the molecular structure of each of the molecules of theorienting material and so as to permit the molecular units of themolecular structure to be aligned along a first axis and to permit theorienting space between each adjacent pair of the molecular units of themolecular structure to be oriented in a direction parallel to a secondaxis, the first and second axes forming a predetermined angletherebetween; and (c) forming an optical anisotropical layer on theorienting film by applying a liquid crystal film of rod-like moleculeson the orienting film which orients the rod-like molecules by virtue ofspatial effect of the molecular units and the orienting spaces among themolecular units of the molecular structure on the rod-like molecules.

According to another aspect of the present invention, an optical devicecomprises: a substrate defining a plane; an orienting film formed on thesubstrate and made from an orienting material having molecules, each ofwhich has a molecular structure that is stretchable and that has aseries of connected molecular units, each adjacent pair of the molecularunits defining an orienting space therebetween, the molecular units ofthe molecular structure being aligned along a first axis, the orientingspace between each adjacent pair of the molecular units of the molecularstructure being oriented in a direction parallel to a second axis, thefirst and second axes forming a predetermined angle therebetween; and anoptical anisotropical layer formed on the orienting film and made from aliquid crystal material of rod-like molecules that are spatiallyaffected and oriented by the molecular units and the orienting spacesamong the molecular units of the molecular structure in an orientingdirection such that the projection of the orienting direction on theplane is parallel to the second axis.

According to yet another aspect of the present invention, an opticaldevice comprises: a substrate defining a plane; an isotropic adhesivelayer made from anisotropic material and formed on the substrate; and anoptical anisotropical layer formed on the isotropic adhesive layer andmade from a liquid crystal material of rod-like molecules that areoriented in a predetermined orienting direction.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeapparent in the following detailed description of the preferredembodiments of the invention, with reference to the accompanyingdrawings. In the drawings:

FIG. 1 is an exploded view of a conventional polarization element;

FIG. 2 is an exploded view of another conventional polarization element;

FIG. 3 is a schematic view of the preferred embodiment, illustrating howan orienting layer is rubbed using a roller having a rubbing directionparallel to a machine direction according to the method of thisinvention;

FIG. 4 is a schematic view of the preferred embodiment, illustrating howan orienting layer is rubbed using a roller having a rubbing directionforming an angle of 30 degrees with a machine direction according to themethod of this invention;

FIG. 5 is a schematic view of the preferred embodiment, illustrating howan orienting layer is rubbed using a roller having a rubbing directionforming an angle of −30 degrees with a machine direction according tothe method of this invention;

FIG. 6 is an exploded view of the first preferred embodiment of anoptical device according to this invention;

FIG. 7 is an exploded view of the second preferred embodiment of anoptical device according to this invention;

FIG. 8 is an exploded view of the third preferred embodiment of anoptical device according to this invention;

FIG. 9 is an exploded view of the fourth preferred embodiment of anoptical device according to this invention;

FIG. 10 is an exploded view of the fifth preferred embodiment of anoptical device according to this invention;

FIG. 11 is an exploded view of the sixth preferred embodiment of anoptical device according to this invention;

FIG. 12 is an exploded view of the seventh preferred embodiment of anoptical device according to this invention;

FIG. 13 is an exploded view of the eighth preferred embodiment of anoptical device according to this invention;

FIG. 14 is an exploded view of the ninth preferred embodiment of anoptical device according to this invention;

FIG. 15 is an exploded view of the tenth preferred embodiment of anoptical device according to this invention;

FIG. 16 is an exploded view of the eleventh preferred embodiment of anoptical device according to this invention;

FIG. 17 is an exploded view of the twelfth preferred embodiment of anoptical device according to this invention;

FIG. 18 is an exploded view of the thirteenth preferred embodiment of anoptical device according to this invention;

FIG. 19 is a schematic view to illustrate how a substrate is conveyedand rubbed using a roller set according to the preferred embodiment ofthe method of this invention; and

FIG. 20 is a schematic view to illustrate how an anisotropical layer istransferred from a first substrate to a second substrate according tothe preferred embodiment of the method of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 6 illustrates the first preferred embodiment of an optical deviceaccording to this invention for connecting to a polarizer 10 that has anabsorbing axis 101. The optical device includes a first substrate 61, afirst orienting film 71, and a first optical isotropic layer 81. Thefirst orienting film 71 and the first substrate 61 cooperately define anorienting layer 700. The polarizer 10 is to be connected to the firstsubstrate 61.

As illustrated in FIG. 3, the optical device is made by a method thatcomprises the steps of: (a) coating the first substrate 61, whichdefines a plane 611 and which is moved in a machine direction 200, withthe first orienting film 71 (see FIG. 6) that is made from an orientingmaterial having molecules, each of which has a molecular structure 4(see FIG. 3) that is stretchable and that has a series of connectedmolecular units 40, each adjacent pair of the molecular units 40defining an orienting space 42 therebetween; (b) rubbing the firstorienting film 71 using a rubbing roller 300 so as to stretch themolecular structure 4 of each of the molecules of the orienting materialand so as to permit the molecular units 40 of the molecular structure 4to be aligned along a first axis 5, which is parallel to a rubbingdirection 5′ that is normal to the rubbing roller 300 in thisembodiment, and to permit the orienting space 42 between each adjacentpair of the molecular units 40 of the molecular structure 4 to beoriented in a direction parallel to a second axis 41, the first andsecond axes 5, 41 forming a predetermined angle θ_(T) therebetween; and(c) forming the first optical anisotropical layer 81 (see FIG. 6) on thefirst orienting film 71 by applying a liquid crystal film of rod-likemolecules 3 (see FIG. 3) on the first orienting film 71. The firstorienting film 71 orients the rod-like molecules 3 of the liquid crystalfilm by virtue of spatial effect of the molecular units 40 and theorienting spaces 42 among the molecular units 40 of the molecularstructure 4 on the rod-like molecules 3 such that the rod-like molecules3 have an oriented angle θ₁ (see FIG. 6) which is defined as an anglebetween the projection 812 of the orientation 811 of the rod-likemolecules 3 on the plane 611 of the first substrate 61 and alongdirection 201 of the first substrate 61. The oriented angle θ₁ will behereinafter referred to the oriented angle θ₁ of the first opticalanisotropical layer 81. Note that the orientation 811 of the rod-likemolecules 3 forms an inclined angle φ_(LC) with the plane 611 of thefirst substrate 61.

The long direction 201 of the first substrate 61 is parallel to themachine direction 200, and is set to be parallel to the absorbing axis101 of the polarizer 10. The oriented angle θ₁ of the rod-like molecules3 is the summation of the angle θ_(T) and a rubbing angle θ_(R) (seeFIGS. 4 and 5), where the rubbing angle θ_(R) is defined as the anglebetween the long direction 201 and the first axis 5 (note that the firstaxis 5 and the rubbing direction 5′ are parallel to each other in theembodiments throughout this specification).

The oriented angle θ₁ of the first optical anisotropical layer 81 can bealtered within a range from 0 degree to 90 degrees by adjusting rubbingparameters, such as the rubbing direction 5′.

In FIG. 3, the rubbing roller 300 is parallel to a transverse directionrelative to the long direction 201 of the first substrate 61 so that thefirst axis 5 is parallel to the long direction 201 of the firstsubstrate 61, i.e., the rubbing angle θ_(R) is 0 degree. As such, theoriented angle θ₁ of the first optical anisotropical layer 81 is equalto the angle θ_(T) between the first and second axes 5, 41.

In FIG. 4, the rubbing roller 300 forms a 30 degree angle with thetransverse direction relative to the long direction 201 of the firstsubstrate 61 so that the first axis 5 forms an angle of 30 degrees withthe long direction 201 of the first substrate 61, i.e., the rubbingangle θ_(R) is 30 degrees. Moreover, the angle θ_(T) between the firstand second axes 5, 41 is equal to 60 degrees. Hence, the oriented angleθ₁ of the first optical anisotropical layer 81 is equal to 90 degrees.

In FIG. 5, the rubbing roller 300 forms a −30 degree angle with thetransverse direction relative to the long direction 201 of the firstsubstrate 61 so that the first axis 5 forms an angle of −30 degrees withthe long direction 201 of the first substrate 61, i.e., the rubbingangle θ_(R) is −30 degrees. Moreover, the angle θ_(T) between the firstand second axes 5, 41 is equal to 30 degrees. Hence, the oriented angleθ₁ of the first optical anisotropical layer 81 is equal to 0 degree.

The angle θ_(T) between the first and second axes 5, 41 can be varied byadding a suitable amount of polyvinyl alcohol in the orienting material.

For the purpose of lowering manufacturing costs, the first substrate 61is made from an inexpensive non-isotropic material. After successfulformation of the first optical anisotropical layer 71 thereon, the firstoptical anisotropical layer 71 is subsequently transferred from thefirst substrate 61 to a second substrate (not shown), which is made froman isotropic material, such as cellulous acetate, that is much moreexpensive than the first substrate 61.

FIG. 7 illustrates the second preferred embodiment of the optical deviceaccording to this invention. The optical device of this embodimentdiffers from the previous embodiment in that a second orienting film 73and a second optical anisotropical layer 82 are further included. Thesecond orienting film 73 is formed on the first optical anisotropicallayer 81, is made from the orienting material, and is rubbed in arubbing direction different from that of the first orienting film 71.The second optical anisotropical layer 82 is formed on the secondorienting film 73, and is made from the liquid crystal material of therod-like molecules that are spatially affected and oriented by thesecond orienting film 73 in a predetermined orientation 821. Thepolarizer 10 is attached to the second optical anisotropical layer 82.The absorbing axis 101 of the polarizer 10 forms a first oriented angleθ₁ with the projection of the orientation 811 of the rod-like moleculesof the first optical anisotropical layer 81 on the plane 611 of thefirst substrate 61, and a second oriented angle θ₂ with the projection822 of the orientation 821 of the rod-like molecules of the secondoptical anisotropical layer 82 on the plane 611 of the first substrate61. In this embodiment, the first and second oriented angles θ₁, θ₂ are75 degrees and 15 degrees, respectively, so that the first and secondoptical anisotropical layers 81, 82 generate a phase difference of λ/4and a phase difference of λ/2 at a wavelength of 550 nm, respectively,where λ is the wavelength of an incident light traveling through theoptical device.

FIG. 8 illustrates the third preferred embodiment of the optical deviceaccording to this invention. The optical device of this embodimentdiffers from the second embodiment in that the first and second orientedangles θ₁, θ₂ are 15 degrees and 75 degrees, respectively, so that thefirst and second optical anisotropical layers 81, 82 generate a phasedifference of λ/2 and a phase difference of λ/4 at a wavelength of 550nm, respectively. The polarizer 10 is attached to the first substrate61.

FIG. 9 illustrates the fourth preferred embodiment of the optical deviceaccording to this invention. The optical device of this embodimentdiffers from the first preferred embodiment in that an isotropicadhesive layer 72 and a second optical anisotropical layer 82 arefurther included. The isotropic adhesive layer 72 is made from anisotropic material. The second optical anisotropical layer 82 is formedon the isotropic adhesive layer 72, and is made from the liquid crystalmaterial of the rod-like molecules that are spatially affected andoriented in a predetermined orientation 821. The polarizer 10 isattached to the second optical anisotropical layer 82. The absorbingaxis 101 of the polarizer 10 forms a first oriented angle θ₁ with theprojection of the orientation 811 of the rod-like molecules of the firstoptical anisotropical layer 81 on the plane 611 of the first substrate61, and a second oriented angle θ₂ with the projection 822 of theorientation 821 of the rod-like molecules of the second opticalanisotropical layer 82 on the plane 611 of the first substrate 61. Inthis embodiment, the first and second oriented angles θ₁, θ₂ are 75degrees and 15 degrees, respectively, so that the first and secondoptical anisotropical layers 81, 82 generate a phase difference of λ/4and a phase difference of λ/2 at a wavelength of 550 nm, respectively.

FIG. 10 illustrates the fifth preferred embodiment of the optical deviceaccording to this invention. The optical device of this embodimentdiffers from the fourth embodiment in that the first and second orientedangles θ₁, θ₂ are 15 degrees and 75 degrees, respectively, so that thefirst and second optical anisotropical layers 81, 82 generate a phasedifference of λ/2 and a phase difference of λ/4 at a wavelength of 550nm, respectively. The polarizer 10 is attached to the first substrate61.

FIG. 11 illustrates the sixth preferred embodiment of the optical deviceaccording to this invention. The optical device of this embodiment issimilar to the first preferred embodiment, except that the opticaldevice further includes a polarizer 10, and serves as a circularpolarizer. In this embodiment, the first substrate 61 is made fromisotropic material, such as cellulous acetate. Moreover, the firstoriented angle is 45 degrees so that the first optical anisotropicallayer 81 generates a phase difference of λ/4 at a wavelength of 550 nm.Conventional circular polarizers normally include a quarter wave plate,an iodine-doped polyvinyl alcohol film, and two cellulous acetate (TAC)films. However, using the method of this invention, only one cellulousacetate film (i.e., the substrate 61) is required in the circularpolarizer of this invention, which results in a reduction in thethickness of the circular polarizer and in lowering manufacturing costs.

FIG. 12 illustrates the seventh preferred embodiment of the opticaldevice according to this invention. The optical device of thisembodiment includes a second substrate 62, an isotropic adhesive layer72 formed on the second substrate 62, and a first optical anisotropicallayer 81 formed on the isotropic adhesive layer 72. The optical devicecan be attached to a polarizer 10 which is to be connected to the secondsubstrate 62. The optical device of this embodiment can be obtained bytransferring the first optical anisotropical layer 71 of the opticaldevice of FIG. 6 from the first substrate 61 to the second substrate 62using the isotropic adhesive layer 72.

FIG. 13 illustrates the eighth preferred embodiment of the opticaldevice according to this invention. The optical device of thisembodiment differs from the seventh preferred embodiment in that anorienting film 73 and a second optical anisotropical layer 82 arefurther included. The orienting film 73 is made from the orientingmaterial used in the first preferred embodiment. The second opticalanisotropical layer 82 is formed on the orienting film 73, and is madefrom the liquid crystal material of the rod-like molecules that arespatially affected and oriented by the orienting film 73 in apredetermined orientation 821. The absorbing axis 101 of the polarizer10 forms a first oriented angle θ₁ with the projection of theorientation 811 of the rod-like molecules of the first opticalanisotropical layer 81 on a plane 621 defined by the second substrate62, and a second oriented angle θ₂ with the projection 822 of theorientation 821 of the rod-like molecules of the second opticalanisotropical layer 82 on the plane 621 of the second substrate 62. Inthis embodiment, the first and second oriented angles θ₁, θ₂ are 15degrees and 75 degrees, respectively, so that the first and secondoptical anisotropical layers 81, 82 generate a phase difference of λ/2and a phase difference of λ/4 at a wavelength of 550 nm, respectively.

FIG. 14 illustrates the ninth preferred embodiment of the optical deviceaccording to this invention. The optical device of this embodimentdiffers from the eighth preferred embodiment in that the first andsecond oriented angles θ₁, θ₂ are 75 degrees and 15 degrees,respectively, so that the first and second optical anisotropical layers81, 82 generate a phase difference of λ/4 and a phase difference of λ/2at a wavelength of 550 nm, respectively. Moreover, the polarizer 10 isto be attached to the second optical anisotropical layer 82 of thisembodiment.

FIG. 15 illustrates the tenth preferred embodiment of the optical deviceaccording to this invention. The optical device of this embodimentdiffers from the seventh preferred embodiment in that a second isotropicadhesive layer 72′ which is made from the isotropic material and whichis formed on the first optical anisotropical layer 81, and a secondoptical anisotropical layer 82 that is bonded to the first opticalanisotropical layer 81 through the second isotropic adhesive layer 72′are included. The second optical anisotropical layer 82 is made from theliquid crystal material of the rod-like molecules that are oriented in apredetermined orientation. In this embodiment, the first and secondoriented angles θ₁, θ₂ are 15 degrees and 75 degrees, respectively, sothat the first and second optical anisotropical layers 81, 82 generate aphase difference of λ/2 and a phase difference of λ/4 at a wavelength of550 nm, respectively.

FIG. 16 illustrates the eleventh preferred embodiment of the opticaldevice according to this invention. The optical device of thisembodiment differs from the tenth preferred embodiment in that the firstand second oriented angles θ₁, θ₂ are 75 degrees and 15 degrees,respectively, so that the first and second optical anisotropical layers81, 82 generate a phase difference of λ/4 and a phase difference of λ/2at a wavelength of 550 nm, respectively. Moreover, the polarizer 10 isto be attached to the second optical anisotropical layer 82 of thisembodiment.

FIG. 17 illustrates the twelfth preferred embodiment of the opticaldevice according to this invention. The optical device of thisembodiment is similar to the seventh preferred embodiment, except thatthe optical device further includes a polarizer 10, and serves as acircular polarizer. Moreover, the first oriented angle is 45 degrees sothat the first optical anisotropical layer 81 generates a phasedifference of λ/4 at a wavelength of 550 nm.

FIG. 18 illustrates the thirteenth preferred embodiment of the opticaldevice according to this invention. The optical device of thisembodiment is similar to the seventh preferred embodiment, except thatthe substrate 62 is itself a polarizer.

The optical device of this invention can be produced in the form of aroll or a rolled film. The thickness of the optical device preferablyranges from 0.01 to 0.5 μm, and is more preferably ranges from 0.05 to0.25 μm.

The first substrate 61 can be made from a non-isotropic material, suchas polyethylene terephthalate (PET), polyethylene, and polypropylene, orfrom an isotropic material, such as cellulous esters, polycarbonate,polysulfone, polycycloolefin, polyether sulfone, polyacrylate, andpolymethacrylate. Preferably, the isotropic material has a transparencygreater than 80%, a R_(e)400/R_(e)700 ratio less than 1.2, and a phaseretardation Re less than 20 nm, and more preferably, has a phaseretardation Re less than 10 nm. Preferably, the first substrate 61 ismade from cellulous acetate.

The first and second orienting films 71, 73 can be made from hardened ornon-hardened orienting material. Preferably, the first and secondorienting films 71, 73 are made from hardened orienting material whichcan provide a better weather resistance, and have a layer thicknessranging from 0.01 to 0.5 μm.

Referring back to FIG. 3, the molecular structure 4 of each of themolecules of the orienting material of the first orienting film 71 ishelical in shape. Preferably, each of the molecules of the orientingmaterial includes a polypeptide with a helical structure. Morepreferably, the orienting material is a mixture of single ormulti-stranded polypeptides, and most preferably the orienting materialis gelatin, such as gelatin from porcine, bovine, or fish skin, ormixtures thereof.

The first orienting film 71 is formed on the first substrate 61 byapplying a solution containing the orienting material to the firstsubstrate 61 and subsequently drying the applied solution on the firstsubstrate 61. Preferably, the solution is an aqueous gelatin thatcontains 0.05 to 20 wt % of gelatin, and more preferably, contains 2 to10 wt % of gelatin. The solution can further contains an alcohol havingfrom 1 to 6 carbon atoms.

The liquid crystal film of the rod-like molecules 3 applied on the firstorienting film 71 for forming the first optical anisotropical layer 81is preferably hardened during step (c). A hardening agent and an acidfor characterizing hardening reaction are added in the solution for thehardening of the liquid crystal film. The hardening operation isconducted at a temperature ranging from 70 to 90° C., followed byradiating the liquid crystal film with UV light.

Suitable hardening agent is selected from the group consisting ofaldehydes, N-methylol compounds, dioxane derivatives, carboxylgroup-containing compounds that can be used for initiating cross-linkingreaction, active vinyl compounds, active halide, isooxazoles, anddialdehyde starch. Preferably, the hardening agent is aldehydes, such asglutaraldehyde.

The amount of the hardening agent used in the solution preferably rangesfrom 0.1 to 20 wt %, and more preferably ranges from 0.5 to 15 wt %,based on the weight of the gelatin in the solution.

Preferably, the acid used in the solution is acetic acid.

Preferably, the drying temperature ranges from 50 to 95° C.

Optionally, the orienting material may further contain polyvinylalcohol. The polyvinyl alcohol preferably has a polymerization degreeranging from 100 to 3000, and more preferably ranging from 100 to 1000,and most preferably ranging from 100 to 500, and a saponification degreeranging from 70 to 10 mol %, more preferably ranging from 80 to 100 mol%, and most preferably ranging from 90 to 100 mol %.

It is known in the art that, for the same amount of a pile impression,the higher the rotating speed of the rubbing roller 300, the greaterstretching extent will be for the molecular structure 4 of each of themolecules of the orienting material, and that for the same rotatingspeed, the larger the pile impression, the smaller will be the angleθ_(T) between the first and second axes 5, 41.

The rubbing roller 300 includes rubbing sheet that is made from amaterial, such as rubber sheet, nylon sheet, polyester sheet, nylonfiber, rayon, polyester fiber (velvet sheet), paper sheet, gauze sheet,and felt sheet.

FIG. 19 illustrates how the first substrate 61 is conveyed by a pair ofconveying rollers 400, and how the substrate 61 is rubbed by the rubbingroller 300.

The rotating speed of the rubbing roller 300 preferably ranges from 100to 1500 rpm. The pile impression of the rubbing roller 300 preferablyranges from 0.05 to 0.5 mm.

Conventionally, the rubbing roller is required to be rotated in adirection against the movement of the substrate so as to achieve thedesired rubbing effect. However, the orienting material used for thefirst orienting film 71 permits achievement of the desired rubbingeffect even when the rubbing roller 300 is rotated in an oppositedirection.

When gelatin is used as the orienting material, and the rubbing angleθ_(R) is set to 0 degree, by adjusting the rubbing parameters and byvarying the composition of the solution of the orienting material, arange of from 30 to 80 degrees can be achieved for the oriented angle θ₁of the thus-formed first anisotropical layer 81. However, when gelatinand polyvinyl alcohol are used as the orienting material, and therubbing angle θ_(R) is set to 0 degree, a range of from 0 to 30 degreescan be achieved for the oriented angle θ₁ of the thus-formed firstanisotropical layer 81.

By adjusting the rubbing angle θ_(R), a range of from 0 to 90 degreescan be easily achieved for the thus-formed oriented angle θ₁ of thefirst anisotropical layer 81.

The liquid crystal material suitable for the first optical anisotropicallayer 81 can be the compounds disclosed in U.S. Patent ApplicationPublication No. U.S. 2004/0100600 A1.

Referring back to FIG. 7, in addition to the steps (a) to (c) describedhereinabove, the method for forming the optical device of the secondpreferred embodiment further includes the steps: (d) applying a solutioncontaining the orienting material to the first optical ansiotropicallayer 81; (e) drying the applied solution so as to form the secondorienting film 73 on the first optical anisotropical layer 81; (f)rubbing the second orienting film 73 on the first optical anisotropicallayer 81; (g) forming a second liquid crystal film of rod-like moleculeson the second orienting film 73 so as to form a second opticalanisotropical layer 82 on the second orienting film 73; and (h)hardening the second liquid crystal film on the second orienting film73.

Referring back to FIGS. 6, 12, and 20, the first optical anisotropicallayer 81 can be transferred from the first substrate 61 (see FIG. 6) tothe second substrate 62 (see FIG. 12) by using an isotropic adhesive,which forms the isotropic adhesive layer 72. The transferring operationis conducted by applying the isotropic adhesive to the second substrate62, attaching the second substrate 62 to the first optical anisotropicallayer 81 through the isotropic adhesive, followed by separating thefirst optical anisotropical layer 81 from the first orienting film 71(see FIG. 20). Alternatively, the isotropic adhesive can be applied tothe first optical anisotropical layer 81 instead of being applied to thesecond substrate 62.

In order to permit separation of the first optical anisotropical layer81 from the first orienting film 71, a surface 611 of the firstsubstrate 61, which is the one bonded to the first orienting film 71, issubjected to corona treatment prior to the formation of the firstorienting film 71 on the surface 611 of the first substrate 61 so as toenhance the bonding strength between the surface 611 of the firstsubstrate 61 and the first orienting film 71 and so as to facilitateseparation of the first optical anisotropical layer 81 from the firstorienting film 71.

The aforesaid isotropic adhesive can be general photo-sensitiveadhesives or pressure-sensitive adhesives.

Referring back to FIGS. 7 and 13, the first and second opticalanisotropical layers 81, 82 can be transferred from the first substrate61 (see FIG. 7) to the second substrate 62 (see FIG. 13) in a similarway as shown in FIGS. 6 and 12 by using an isotropic adhesive, whichforms the isotropic adhesive layer 72, and the corona treatment.

Hence, in order to permit separation of the first and second opticalanisotropical layers 81, 82 from the first orienting film 71, a surfaceof the first optical anisotropical layer 81, which is distal from thefirst orienting film 71, is subjected to corona treatment prior to theformation of the second orienting film 73 on the surface of the firstoptical anisotropical layer 81 so as to enhance the bonding strengthbetween the surface of the first optical anisotropical layer 81 and thesecond orienting film 73, and a surface of the second orienting film 73,which is distal from the first optical anisotropical layer 81, is alsosubjected to corona treatment prior to the formation of the secondoptical anisotropical layer 82 on the second orienting film 73 so as toenhance the bonding strength between the surface of the second orientingfilm 73 and the second optical anisotropical layer 82 and so as tofacilitate separation of the first and second optical anisotropicallayers 81, 82 from the first orienting film 71.

In a similar way, referring back to FIGS. 9 and 15, and FIGS. 10 and 16,the first and second optical anisotropical layers 81, 82 can betransferred from the first substrate 61 to the second substrate 62 usingthe abovementioned transfer techniques.

EXAMPLES

This invention will now be described in greater detail with reference tothe following Examples.

Materials and Equipment

The following are details of the materials and equipment used in thefollowing Examples.

1. fish gelatin: purchased from Norland Co., catalogue No.: P/NFG-04.

2. porcine gelatin: purchased from Sigma Co., product name: Gelatin typeA from porcine skin approx. 300 bloom or 175 bloom.

3. bovine gelatin: purchased from Sigma Co., product name: Gelatin typeB from bovine skin approx. 225 bloom.

4. polyvinyl alcohol: purchased from Taiwan ChangChun Plastics Co.,product name: BP-05, polymerization degree: 500, saponification degree:86-89 mol %.

5. rod-like liquid crystal material: purchased from Merk Co., catalogueNo.: RMS03011 for O-plate, and RMS03001 for A-plate.

6. cellulous ester: purchased from Konica Co.

7. rubbing machine having a rubbing roller with rayon rubbing sheet.

Example 1

Preparation of the Optical Device

The optical device for Example 1 was prepared according to the followingconsecutive steps:

(1) preparing an aqueous orienting solution by adding 0.5 g of the fishgelatin into 100 ml of water which was kept at a temperature of 60° C.;

(2) applying the orienting solution to a PET film using gravuretechniques to form a 0.2 g m thick orienting coating on the PET film;

(3) baking the orienting coating at a temperature of 90° C. for about 3minutes;

(4) rubbing the baked orienting coating using the rubbing roller under arubbing angle θ_(R) equal to 0 degree, a pile impression of 0.3 mm, anda roller rotating speed of 600 rpm so as to form the orienting coatinginto an orienting film;

(5) applying the rod-like liquid crystal material (RMS03011) to theorienting film so as to form a 1.1-1.5 μm thick liquid crystal coatingon the orienting film;

(6) heating the liquid crystal coating at a temperature of about 80° C.for about one minute for alignment of the rod-like liquid crystalmolecules on the orienting film so as to form a wet film; and

(7) radiating the wet film with a UV exposure machine under a power of0.2 J/cm² so as to harden the rod-like liquid crystal molecules and soas to form an optical anisotropical layer on the orienting film. Theoptical device thus-formed was in the form of a roll.

Measuring of the Oriented Angle

The oriented angle θ of the optical anisotropical layer obtained fromExample 1 was measured using an Ellipsometer, and was about 60 degrees.

Example 2

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by adding 0.35 g porcine skin gelatin (300bloom), 0.23 g fish gelatin, 0.1 g acetic acid, and 0.1 g glutaraldehyde(concentration: 25 wt %) into a mixture of 15 g water, 15 g methanol,and 8 g acetone. The oriented angle θ of the optical anisotropical layerobtained from Example 2 was measured, and was 40 degrees.

Example 3

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by adding 2 g porcine skin gelatin (300bloom), 1 g salicylic acid, and 3.5 g formaldehyde (concentration: 37 wt%) into a mixture of 10 g water, 10 g methanol, and 25 g acetone. Theoriented angle θ of the optical anisotropical layer obtained fromExample 3 was measured, and was 40 degrees.

Example 4

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by adding 0.5 g bovine skin gelatin, 0.5 gsalicylic acid, and 2.5 g formaldehyde (concentration: 10 wt %) into amixture of 5 g water, 5 g methanol, and 10 g acetone. The orientingcoating was baked at a temperature of 80° C. Moreover, the RMS03001 wasused as the rod-like liquid crystal material. The oriented angle θ ofthe optical anisotropical layer obtained from Example 4 was measured,and was 45 degrees, which permits the use of the optical device of thisExample as a quarter wave plate.

Example 5

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by dissolving 0.5 g porcine skin gelatin (300bloom) in 20 g water. The water was kept at a temperature of 65° C.during the dissolution of the gelatin. The roller rotating speed was1400 rpm during the rubbing operation. The oriented angle θ of theoptical anisotropical layer obtained from Example 5 was measured, andwas 40 degrees.

Example 6

This Example differs from Example 5 in that the roller rotating speedwas 1000 rpm during the rubbing operation. The oriented angle θ of theoptical anisotropical layer obtained from Example 6 was measured, andwas 50 degrees.

Example 7

This Example differs from Example 5 in that the roller rotating speedwas 800 rpm during the rubbing operation. The oriented angle θ of theoptical anisotropical layer obtained from Example 7 was measured, andwas 60 degrees.

Example 8

This Example differs from Example 5 in that the roller rotating speedwas 200 rpm during the rubbing operation. The oriented angle θ of theoptical anisotropical layer obtained from Example 8 was measured, andwas 70 degrees.

Example 9

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by adding 0.5 g bovine skin gelatin, 0.25 gacetic acid, and 5 g formaldehyde (concentration: 10 wt %) into amixture of 5 g water, 4.5 g methanol, and 3 g acetone. In addition, theorienting coating was baked at a temperature of 85° C. The orientedangle θ of the optical anisotropical layer obtained from Example 9 wasmeasured, and was 75 degrees.

Example 10

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by adding 0.5 g bovine skin gelatin and 0.2 gacetic acid into a mixture of 10 g water and 5 g methanol. In addition,the orienting coating was baked at a temperature of 85° C. The orientedangle θ of the optical anisotropical layer obtained from Example 10 wasmeasured, and was 80 degrees.

Example 11

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by adding 0.5 g bovine skin gelatin, 1 gpolyvinyl alcohol (10 wt %), 0.2 g acetic acid, and 2.5 g formaldehyde(concentration: 10 wt %) into a mixture of 10 g water, 5 g methanol, and5 g acetone. In addition, the orienting coating was baked at atemperature of 85° C. The oriented angle θ of the optical anisotropicallayer obtained from Example 11 was measured, and was 0 degree.

Example 12

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by dissolving 0.5 g bovine skin gelatin in 15g water under a temperature of 65° C., followed by adding 0.1 gpolyvinyl alcohol (10 wt %), 0.1 g acetic acid, 0.1 g glutaraldehyde(concentration: 37 wt %), 5 g methanol, and 8 g acetone into the aqueousgelatin solution. The oriented angle θ of the optical anisotropicallayer obtained from Example 12 was measured, and was 3 degrees.

Example 13

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by dissolving 0.5 g bovine skin gelatin in 15g water under a temperature of 65° C., followed by adding 0.05 gpolyvinyl alcohol (10 wt %), 0.1 g acetic acid, 5 g formaldehyde(concentration: 10 wt %), 5 g methanol, and 7 g acetone into the aqueousgelatin solution. Moreover, the RMS03001 was used as the rod-like liquidcrystal material. The oriented angle θ of the optical anisotropicallayer obtained from Example 13 was measured, and was 15 degrees.

Example 14

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by dissolving 0.5 g porcine skin gelatin (300bloom) in a mixture of 50 g water, 13 g methanol, and 18 g acetone undera temperature of 65C. The rubbing operation was conducted under arubbing angle θ_(R) of 30 degrees and a roller rotating speed of 300rpm. The oriented angle θ of the optical anisotropical layer obtainedfrom Example 14 was measured, and was 75 degrees.

Example 15

This Example differs from Example 1 in that the orienting solution ofthis Example was prepared by dissolving 6 g porcine skin gelatin (175bloom) in a mixture of 60 g water, 17 g methanol, 30 g acetone, 6 gformaldehyde (concentration: 10 wt %), and 0.6 g acetic acid under atemperature of 65C. The rubbing operation was conducted under a rubbingangle θ_(R) of 15 degrees and a roller rotating speed of 150 rpm. Theoriented angle θ of the optical anisotropical layer obtained fromExample 15 was measured, and was 75 degrees.

Example 16

This Example differs from Example 15 in that the roller rotating speedwas 100 rpm. The oriented angle θ of the optical anisotropical layerobtained from Example 16 was measured, and was 75 degrees.

Example 17

This Example differs from Example 9 in that the rubbing angle θ_(R) was15 degrees. The oriented angle θ of the optical anisotropical layerobtained from Example 17 was measured, and was 90 degrees.

Example 18

This Example differs from Example 9 in that the PET film was subjectedto corona treatment prior to the application of the orienting solutionto the PET film, and that the optical anisotropical layer wastransferred from the PET film to a cellulous acetate film using aphoto-sensitive adhesive. The optical device thus-formed was similar tothe one shown in FIG. 18.

Example 19

The optical device of this Example was prepared by further processingthe optical device obtained from Example 9 according to the followingsteps (i.e., after step (7) in Example 1):

(8) applying the orienting solution obtained from Example 13 to thefirst optical anisotropical layer of the optical device obtained fromExample 9 so as to form an orienting coating on the first opticalanisotropical layer;

(9) drying the orienting coating;

(10) rubbing the dried orienting coating using the rubbing roller undera rubbing angle θ_(R) equal to 0 degree so as to form a second orientingfilm;

(11) applying the RMS03001 type rod-like liquid crystal material (i.e.,the same material used in Example 13) to the second orienting film so asto form a liquid crystal coating on the second orienting film;

(12) heating the liquid crystal coating at a temperature of about 80° C.for about one minute for alignment of the rod-like liquid crystalmolecules on the second orienting film so as to form a wet film; and

(13) radiating the wet film with a UV exposure machine under a power of0.2 J/cm² so as to harden the rod-like liquid crystal molecules and soas to form a second optical anisotropical layer on the second orientingfilm.

The oriented angle of the second optical anisotropical layers wasmeasured, and was 15 degrees (i.e., the same as that of Example 13).

Example 20

This Example differs from Example 19 in that the PET film was subjectedto corona treatment prior to the application of the orienting solutionto the PET film, that the first optical anisotropical layer wassubjected to corona treatment prior to the application of the orientingsolution to the first optical anisotropical layer, and that the secondoriented film was subjected to corona treatment prior to the applicationof the liquid crystal material to the second orienting film. The firstand second optical anisotropical layers were subsequently transferred toa cellulous acetate substrate using a photo-sensitive adhesive.

Example 21

This Example is opposite to Example 19 such that the first opticalanisotropical layer was obtained from Example 13 and the second opticalanisotropical layer was obtained from Example 9.

Example 22

This Example differs from Example 21 in that the PET film was subjectedto corona treatment prior to the application of the orienting solutionto the PET film, that the first optical anisotropical layer wassubjected to corona treatment prior to the application of the orientingsolution to the first optical anisotropical layer, and that the secondorienting film was subjected to corona treatment prior to theapplication of the liquid crystal material to the second orienting film.The first and second optical anisotropical layers were subsequentlytransferred to a cellulous acetate substrate using a photo-sensitiveadhesive.

Example 23

The optical device of this Example was prepared by coating aphoto-sensitive adhesive to the first optical anisotropical layer of theoptical device obtained from Example 9, attaching the optical deviceobtained from Example 13 to that of Example 9 through thephoto-sensitive adhesive, and separating the optical anisotropicallayers of the assembly from the orienting film of the optical device ofExample 13.

Example 24

This Example differs from Example 23 in that the PET film in Example 9was subjected to corona treatment prior to the application of theorienting solution thereto, and that the first and second opticalanisotropical layers of the assembly were transferred from the orientingfilm of the optical device obtained from Example 9 to a cellulousacetate film through a photo-sensitive adhesive.

Example 25

This Example differs from Example 23 in that the optical device of thisExample was prepared by coating a photo-sensitive adhesive to the firstoptical anisotropical layer of the optical device obtained from Example13, attaching the optical device obtained from Example 9 to that ofExample 13 through the photo-sensitive adhesive, and separating theoptical anisotropical layers of the assembly from the orienting film ofthe optical device of Example 9.

Example 26

This Example differs from Example 25 in that the PET film in Example 13was subjected to corona treatment prior to the application of theorienting solution thereto, and that the first and second opticalanisotropical layers of the assembly were transferred from the orientingfilm of the optical device obtained from Example 13 to a cellulousacetate film through a photo-sensitive adhesive.

Example 27

The optical device of this Example was prepared by attaching a cellulousacetate film to an iodine-doped polyvinyl alcohol film in a roll-to-rollmanner so as to form a rolled polarizer, followed by attaching theoptical device obtained from Example 4 to the rolled polarizer in aroll-to-roll manner so as to form a circular polarizer.

While the present invention has been described in connection with whatis considered the most practical and preferred embodiments, it isunderstood that this invention is not limited to the disclosedembodiments but is intended to cover various arrangements includedwithin the spirit and scope of the broadest interpretations andequivalent arrangements.

1. A method for making an optical device, comprising the steps of: (a) providing a first orienting film that is made from an orienting material having molecules, each of which has a molecular structure that is stretchable and that has a series of connected molecular units, each adjacent pair of the molecular units defining an orienting space therebetween; (b) rubbing the first orienting film so as to stretch the molecular structure of each of the molecules of the orienting material and so as to permit the molecular units of the molecular structure to be aligned along a first axis and to permit the orienting space between each adjacent pair of the molecular units of the molecular structure to be oriented in a direction parallel to a second axis, the first and second axes forming a predetermined angle therebetween; and (c) forming a first optical anisotropical layer on the first orienting film by applying a first liquid crystal film of rod-like molecules on the first orienting film which orients the rod-like molecules by virtue of spatial effect of the molecular units and the orienting spaces among the molecular units of the molecular structure on the rod-like molecules.
 2. The method of claim 1, wherein the molecular structure of each of the molecules of the orienting material is helical in shape.
 3. The method of claim 1, wherein each of the molecules of the orienting material includes a polypeptide with a helical structure.
 4. The method of claim 1, wherein the orienting material comprises gelatin.
 5. The method of claim 1, further comprising the step of forming the first orienting film on a first substrate prior to step (b).
 6. The method of claim 4, further comprising the step of forming the first orienting film on a first substrate prior to step (b).
 7. The method of claim 5, wherein the first orienting film has a layer thickness ranging from 0.01 to 0.50 μm.
 8. The method of claim 6, wherein the first orienting film has a layer thickness ranging from 0.01 to 0.50 μm.
 9. The method of claim 5, wherein the first orienting film is hardened after forming on the first substrate.
 10. The method of claim 6, wherein the first orienting film is hardened after forming on the first substrate.
 11. The method of claim 1, wherein the first orienting film is rubbed by a rubbing roller in step (b) under a pile impression ranging from 0.05 mm to 0.5 mm and a roller rotating speed ranging from 100 rpm to 1500 rpm.
 12. The method of claim 4, wherein the first orienting film is rubbed by a rubbing roller in step (b) under a pile impression ranging from 0.05 mm to 0.5 mm and a roller rotating speed ranging from 100 rpm to 1500 rpm.
 13. The method of claim 5, wherein, in step (b), the first substrate is moved along a long direction, and the rubbing roller is disposed in a position relative to the first substrate in such a manner so as to rub the first orienting film in a rubbing direction that forms a rubbing angle with the long direction, the rubbing angle ranging from −45 to 45 degrees.
 14. The method of claim 6, wherein, in step (b), the first substrate is moved along a long direction, and the rubbing roller is disposed in a position relative to the first substrate in such a manner so as to rub the first orienting film in a rubbing direction that forms a rubbing angle with the long direction, the rubbing angle ranging from −45 to 45 degrees.
 15. The method of claim 1, wherein the first orienting film further comprises polyvinyl alcohol.
 16. The method of claim 4, wherein the first orienting film further comprises polyvinyl alcohol.
 17. The method of claim 15, wherein the polyvinyl alcohol has a polymerization degree ranging from 100 to
 3000. 18. The method of claim 16, wherein the polyvinyl alcohol has a polymerization degree ranging from 100 to
 3000. 19. The method of claim 15, wherein the polyvinyl alcohol has a saponification degree ranging from 70 mol % to 100 mol %.
 20. The method of claim 16, wherein the polyvinyl alcohol has a saponification degree ranging from 70 mol % to 100 mol %.
 21. The method of claim 5, wherein the first orienting film is formed on the first substrate by applying a solution containing the orienting material to the first substrate and subsequently drying the applied solution on the first substrate.
 22. The method of claim 6, wherein the first orienting film is formed on the first substrate by applying a solution containing the orienting material to the first substrate and subsequently drying the applied solution on the first substrate.
 23. The method of claim 21, wherein the solution further contains water.
 24. The method of claim 22, wherein the solution further contains water.
 25. The method of claim 21, wherein the solution further contains a hardening agent and an acid.
 26. The method of claim 22, wherein the solution further contains a hardening agent and an acid.
 27. The method of claim 25, wherein the hardening agent is an aldehyde.
 28. The method of claim 26, wherein the hardening agent is an aldehyde.
 29. The method of claim 23, wherein the solution further contains an alcohol having from 1 to 6 carbon atoms so as to control hardening rate of the first orienting film.
 30. The method of claim 24, wherein the solution further contains an alcohol having from 1 to 6 carbon atoms so as to control hardening rate of the first orienting film.
 31. The method of claim 1, further comprising the step of hardening the first liquid crystal film on the first orienting film after step (c).
 32. The method of claim 4, further comprising the step of hardening the first liquid crystal film on the first orienting film after step (c).
 33. The method of claim 31, further comprising the step of forming the first orienting film on a first substrate prior to step (b).
 34. The method of claim 32, further comprising the step of forming the first orienting film on a first substrate prior to step (b).
 35. The method of claim 33, further comprising the steps of: (d) applying a solution containing the orienting material to the first optical ansiotropical layer; (e) drying the applied solution so as to form a second orienting film on the first optical anisotropical layer; (f) rubbing the second orienting film on the first optical anisotropical layer; (g) forming a second liquid crystal film of rod-like molecules on the second orienting film so as to form a second optical anisotropical layer on the second orienting film; and (h) hardening the second liquid crystal film on the second orienting film.
 36. The method of claim 34, further comprising the steps of: (d) applying a solution containing the orienting material to the first optical ansiotropical layer; (e) drying the applied solution so as to form a second orienting film on the first optical anisotropical layer; (f) rubbing the second orienting film on the first optical anisotropical layer; (g) forming a second liquid crystal film of rod-like molecules on the second orienting film so as to form a second optical anisotropical layer on the second orienting film; and (h) hardening the second liquid crystal film on the second orienting film.
 37. The method of claim 35, wherein, in step (f), the first substrate is moved along a long direction, the second orienting film being rubbed in a rubbing direction that forms a rubbing angle with the long direction, the rubbing angle ranging from −45 to 45 degrees.
 38. The method of claim 36, wherein, in step (f), the first substrate is moved along a long direction, the second orienting film being rubbed in a rubbing direction that forms a rubbing angle with the long direction, the rubbing angle ranging from −45 to 45 degrees.
 39. The method of claim 5, further comprising the step of subjecting a surface of the first substrate to corona treatment prior to the formation of the first orienting film on the surface of the first substrate so as to enhance bonding strength between the surface of the first substrate and the first orienting film.
 40. The method of claim 6, further comprising the step of subjecting a surface of the first substrate to corona treatment prior to the formation of the first orienting film on the surface of the first substrate so as to enhance bonding strength between the surface of the first substrate and the first orienting film.
 41. The method of claim 39, further comprising the step of transferring the first optical anisotropical layer from the first substrate to a second substrate including applying an adhesive to the second substrate, attaching the second substrate to the first optical anisotropical layer through the adhesive, followed by separating the first optical anisotropical layer from the first orienting film.
 42. The method of claim 40, further comprising the step of transferring the first optical anisotropical layer from the first substrate to a second substrate including applying an adhesive to the second substrate, attaching the second substrate to the first optical anisotropical layer through the adhesive, followed by separating the first optical anisotropical layer from the first orienting film.
 43. The method of claim 41, wherein the second substrate is made from an isotropic material.
 44. The method of claim 42, wherein the second substrate is made from an isotropic material.
 45. The method of claim 41, wherein the second substrate is a polarizer.
 46. The method of claim 42, wherein the second substrate is a polarizer.
 47. The method of claim 41, wherein the adhesive is made from an isotropic adhesive.
 48. The method of claim 42, wherein the adhesive is made from an isotropic adhesive.
 49. The method of claim 41, further comprising the step of subjecting a surface of the first optical anisotropical layer, which is distal from the first orienting film, to corona treatment.
 50. The method of claim 42, further comprising the step of subjecting a surface of the first optical anisotropical layer, which is distal from the first orienting film, to corona treatment.
 51. The method of claim 49, further comprising the steps of: applying a solution containing the orienting material to the treated surface of the first optical ansiotropical layer; drying the applied solution so as to form a second orienting film on the first optical anisotropical layer; rubbing the second orienting film on the first optical anisotropical layer; subjecting a surface of the second orienting film, which is distal from the first optical anisotropical layer, to corona treatment; forming a second optical anisotropical layer on the second orienting film by applying a second liquid crystal film of rod-like molecules on the treated surface of the second orienting film; and hardening the second liquid crystal film on the second orienting film.
 52. The method of claim 51, further comprising the steps of: applying a solution containing the orienting material to the treated surface of the first optical ansiotropical layer; drying the applied solution so as to form a second orienting film on the first optical anisotropical layer; rubbing the second orienting film on the first optical anisotropical layer; subjecting a surface of the second orienting film, which is distal from the first optical anisotropical layer, to corona treatment; forming a second optical anisotropical layer on the second orienting film by applying a second liquid crystal film of rod-like molecules on the treated surface of the second orienting film; and hardening the second liquid crystal film on the second orienting film.
 53. The method of claim 51, further comprising the step of transferring the first and second optical anisotropical layers from the first substrate to a second substrate including applying an adhesive to the second substrate, attaching the second substrate to the second optical anisotropical layer through the adhesive, followed by separating the first optical anisotropical layer from the first orienting film.
 54. The method of claim 52, further comprising the step of transferring the first and second optical anisotropical layers from the first substrate to a second substrate including applying an adhesive to the second substrate, attaching the second substrate to the second optical anisotropical layer through the adhesive, followed by separating the first optical anisotropical layer from the first orienting film.
 55. An optical device comprising: a first substrate defining a plane; a first orienting film formed on said first substrate and made from an orienting material having molecules, each of which has a molecular structure that is stretchable and that has a series of connected molecular units, each adjacent pair of said molecular units defining an orienting space therebetween, said molecular units of said molecular structure being aligned along a first axis, said orienting space between each adjacent pair of said molecular units of the molecular structure being oriented in a direction parallel to a second axis, said first and second axes forming a predetermined angle therebetween; and a first optical anisotropical layer formed on said first orienting film and made from a liquid crystal material of rod-like molecules that are spatially affected and oriented by said molecular units and said orienting spaces among said molecular units of said molecular structure such that the projection of the orientation of said rod-like molecules on said plane is parallel to said second axis.
 56. The optical device of claim 55, wherein said molecular structure of each of said molecules of said orienting material is helical in shape.
 57. The optical device of claim 55, wherein each of said molecules of said orienting material is a polypeptide.
 58. The optical device of claim 55, wherein said orienting material comprises gelatin.
 59. The optical device of claim 55, wherein the assembly of said substrate, said first orienting film, and said first optical anisotropical layer is in the form of a roll.
 60. The optical device of claim 55, wherein said first substrate is made from an isotropic material.
 61. The optical device of claim 58, wherein said first substrate is made from an isotropic material.
 62. The optical device of claim 55, wherein said first orienting film has a layer thickness ranging from 0.01 to 0.1 μm.
 63. The optical device of claim 58, wherein said first orienting film has a layer thickness ranging from 0.01 to 0.1 μm.
 64. The optical device of claim 55, wherein said first orienting film further comprises polyvinyl alcohol.
 65. The optical device of claim 58, wherein said first orienting film further comprises polyvinyl alcohol.
 66. The optical device of claim 64, wherein said polyvinyl alcohol has a polymerization degree ranging from 100 to
 3000. 67. The optical device of claim 65, wherein said polyvinyl alcohol has a polymerization degree ranging from 100 to
 3000. 68. The optical device of claim 64, wherein said polyvinyl alcohol has a saponification degree ranging from 70 mol % to 100 mol %.
 69. The optical device of claim 65, wherein said polyvinyl alcohol has a saponification degree ranging from 70 mol % to 100 mol %.
 70. The optical device of claim 55, wherein said first orienting film is hardened.
 71. The optical device of claim 58, wherein said first orienting film is hardened.
 72. The optical device of claim 55, further comprising a polarizer attached to said first substrate, said polarizer having an absorbing axis that forms an angle with the projection of the orientation of said rod-like molecules on said plane, said angle ranging from 0 degree to 90 degrees.
 73. The optical device of claim 58, further comprising a polarizer attached to said first substrate, said polarizer having an absorbing axis that forms an angle with the projection of the orientation of said rod-like molecules on said plane, said angle ranging from 0 degree to 90 degrees.
 74. The optical device of claim 55, further comprising a second orienting film formed on said first optical anisotropical layer, and a second optical anisotropical layer formed on said second orienting film, said second orienting film being made from said orienting material, said second optical anisotropical layer being made from said liquid crystal material of said rod-like molecules that are spatially affected and oriented by said second orienting film.
 75. The optical device of claim 58, further comprising a second orienting film formed on said first optical anisotropical layer, and a second optical anisotropical layer formed on said second orienting film, said second orienting film being made from said orienting material, said second optical anisotropical layer being made from said liquid crystal material of said rod-like molecules that are spatially affected and oriented by said second orienting film.
 76. The optical device of claim 74, further comprising a polarizer attached to one of said first substrate and said second optical anisotropical layer, said polarizer having an absorbing axis that forms a first oriented angle with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane, and a second oriented angle with the projection of the orientation of said rod-like molecules of said second optical anisotropical layer on said plane.
 77. The optical device of claim 75, further comprising a polarizer attached to one of said first substrate and said second optical anisotropical layer, said polarizer having an absorbing axis that forms a first oriented angle with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane, and a second oriented angle with the projection of the orientation of said rod-like molecules of said second optical anisotropical layer on said plane.
 78. The optical device of claim 76, wherein said polarizer is attached to said first substrate, said first and second oriented angles being 15 and 75 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/2 and a phase difference of λ/4 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 79. The optical device of claim 77, wherein said polarizer is attached to said first substrate, said first and second oriented angles being 15 and 75 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/2 and a phase difference of λ/4 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 80. The optical device of claim 76, wherein said polarizer is attached to said second optical anisotropical layer, said first and second oriented angles are 75 and 15 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/4 and a phase difference of λ/2 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 81. The optical device of claim 76, wherein said polarizer is attached to said second optical anisotropical layer, said first and second oriented angles are 75 and 15 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/4 and a phase difference of λ/2 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 82. The optical device of claim 55, further comprising an isotropic adhesive layer that is made from an isotropic material and that is formed on said first optical anisotropical layer, and a second optical anisotropical layer that is formed on said isotropic adhesive layer and that is made from said liquid crystal material of said rod-like molecules which are oriented in a predetermined orientation.
 83. The optical device of claim 58, further comprising an isotropic adhesive layer that is made from an isotropic material and that is formed on said first optical anisotropical layer, and a second optical anisotropical layer that is formed on said isotropic adhesive layer and that is made from said liquid crystal material of said rod-like molecules which are oriented in a predetermined orientation.
 84. The optical device of claim 82, further comprising a polarizer attached to one of said first substrate and said second optical anisotropical layer, said polarizer having an absorbing axis that forms a first oriented angle with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane, and a second oriented angle with the projection of the orientation of said second rod-like molecules of said second optical anisotropical layer on said plane.
 85. The optical device of claim 83, further comprising a polarizer attached to one of said first substrate and said second optical anisotropical layer, said polarizer having an absorbing axis that forms a first oriented angle with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane, and a second oriented angle with the projection of the orientation of said second rod-like molecules of said second optical anisotropical layer on said plane.
 86. The optical device of claim 84, wherein said polarizer is attached to said first substrate, said first and second oriented angles being 15 and 75 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/2 and a phase difference of λ/4 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 87. The optical device of claim 85, wherein said polarizer is attached to said first substrate, said first and second oriented angles being 15 and 75 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/2 and a phase difference of λ/4 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 88. The optical device of claim 84, wherein said polarizer is attached to said second optical anisotropical layer, said first and second oriented angles being 75 and 15 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/4 and a phase difference of λ/2 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 89. The optical device of claim 85, wherein said polarizer is attached to said second optical anisotropical layer, said first and second oriented angles being 75 and 15 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/4 and a phase difference of λ/2 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 90. The optical device of claim 55, further comprising a polarizer attached to said first substrate, said first substrate being made from an isotropic material.
 91. The optical device of claim 58, further comprising a polarizer attached to said first substrate, said first substrate being made from an isotropic material.
 92. The optical device of claim 90, wherein said polarizer has an absorbing axis that forms a first oriented angle of 45 degrees with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane, so that said first optical anisotropical layer generates a phase difference of λ/4 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 93. The optical device of claim 91, wherein said polarizer has an absorbing axis that forms a first oriented angle of 45 degrees with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane, so that said first optical anisotropical layer generates a phase difference of λ/4 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 94. The optical device of claim 90, wherein said first substrate is made from cellulous acetate.
 95. The optical device of claim 91, wherein said first substrate is made from cellulous acetate.
 96. The optical device of claim 94, wherein said polarizer includes a cellulous acetate film and an iodine-doped polyvinyl alcohol film that is bonded to said cellulous acetate film and that is attached to said first substrate.
 97. The optical device of claim 95, wherein said polarizer includes a cellulous acetate film and an iodine-doped polyvinyl alcohol film that is bonded to said cellulous acetate film and that is attached to said first substrate.
 98. An optical device comprising: a substrate defining a plane; a first isotropic adhesive layer made from an isotropic material and formed on said substrate; and a first optical anisotropical layer formed on said isotropic adhesive layer and made from a liquid crystal material of rod-like molecules that are oriented in a predetermined direction.
 99. The optical device of claim 98, wherein said substrate is made from an isotropic material.
 100. The optical device of claim 98, further comprising an orienting film that is formed on said first optical anisotropical layer, and a second optical anisotropical layer that is formed on said orienting film, said orienting film being made from an orienting material having molecules, each of which has a molecular structure that is stretchable and that has a series of connected molecular units, each adjacent pair of said molecular units defining an orienting space therebetween, said molecular units of said molecular structure being aligned along a first axis, said orienting space between each adjacent pair of said molecular units of the molecular structure being oriented in a direction parallel to a second axis, said first and second axes forming a predetermined angle therebetween, said second optical anisotropical layer being made from said liquid crystal material of said rod-like molecules that are spatially affected and oriented by said molecular units and said orienting spaces among said molecular units of said molecular structure of each of said molecules of said orienting film such that the projection of the orientation of said rod-like molecules of said second optical anisotropical layer on said plane is parallel to said second axis.
 101. The optical device of claim 100, further comprising a polarizer attached to one of said substrate and said second optical anisotropical layer, said polarizer having an absorbing axis that forms a first oriented angle with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane, and a second oriented angle with the projection of the orientation of said second optical anisotropical layer on said plane.
 102. The optical device of claim 101, wherein said polarizer is attached to said substrate, said first and second oriented angles being 15 and 75 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/2 and a phase difference of λ/4 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 103. The optical device of claim 101, wherein said polarizer is attached to said second optical anisotropical layer, said first and second oriented angles are 75 and 15 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/4 and a phase difference of λ/2 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 104. The optical device of claim 98, further comprising a second isotropic adhesive layer that is made from said isotropic material and that is formed on said first optical anisotropical layer, and a second optical anisotropical layer that is bonded to said first optical anisotropical layer through said second isotropic adhesive layer, said second optical anisotropical layer being made from said liquid crystal material of said rod-like molecules that are oriented in a predetermined orientation.
 105. The optical device of claim 104, further comprising a polarizer attached to one of said substrate and said second optical anisotropical layer, said polarizer having an absorbing axis that forms a first oriented angle with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane, and a second oriented angle with the projection of the orientation of said rod-like molecules of said second optical anisotropical layer on said plane.
 106. The optical device of claim 105, wherein said polarizer is attached to said substrate, said first and second oriented angles being 15 and 75 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/2 and a phase difference of λ/4 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 107. The optical device of claim 105, wherein said polarizer is attached to said second optical anisotropical layer, said first and second oriented angles being 75 and 15 degrees, respectively, so that said first and second optical anisotropical layers generate a phase difference of λ/4 and a phase difference of λ/2 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device.
 108. The optical device of claim 98, further comprising a polarizer attached to said substrate, said polarizer having an absorbing axis that forms an oriented angle of 45 degrees with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane so that said first optical anisotropical layer generates a phase difference of λ/4 at a wavelength of 550 nm, where λ is the wavelength of an incident light traveling through said optical device.
 109. The optical device of claim 98, wherein said substrate includes a polarizer with an absorbing axis that forms an oriented angle of 45 degrees with the projection of the orientation of said rod-like molecules of said first optical anisotropical layer on said plane so that said first optical anisotropical layer generates a phase difference of λ/4 at a wavelength of 550 nm, respectively, where λ is the wavelength of an incident light traveling through said optical device. 